UNITED STATES—By now most people have already acquired their Christmas trees. Some are live trees in containers. Some are artificial. Most are cut firs, pines, or alternatively, spruces, cedars, cypresses or even junipers. For at least the next two weeks, these trees dutifully maintain their healthy green vigor to brighten our homes with Christmas cheer.

Cut trees should have no problem lasting from the time they were originally cut through Christmas, as long as they get plenty of water. Artificial trees do not have much choice in the matter. Live trees are probably more reliable than cut trees are in regard to freshness, but can be more awkward to accommodate in the home, since they are more likely to leak excess water that can damage floors. If they they get a bit dry, live trees can also be sensitive to relatively dry and warm interior air after spending autumn out in cool and humid garden environments.

The main problem with living Christmas trees though, begins after Christmas. Spruces and other compact evergreens that can work as Christmas trees for several years need to be returned to the garden and maintained until next Christmas. Retired living Christmas trees, including those common, small trees that can be purchased with a few decorations already wired to their stems, eventually need to be planted out into the garden. Circling roots (that grow around the perimeter of a container in search of a way out) need to be severed so that they do not get constricted as they mature.

Unfortunately, with few exceptions, living Christmas trees mature into significant trees when they get the chance to grow. Those common, pre-decorated trees are most commonly juvenile Italian stone pine or Canary Island pine, which become very large trees. Because they seem so innocent as small potted trees, they often get planted in very awkward situations where they do not have enough space to grow without damaging nearby features.

Planting such a tree out in a forest is not practical, since it will not survive through the first year without supplemental watering. Their roots are just too confined to reach out for moisture. Even if such a tree could survive, it would not be an asset to the forest, since it would be an exotic (non-native) species.

Highlight: English Yew

It is difficult to know how big any of the various cultivars of English yew, Taxus baccata, will eventually get, and how long they will take to get that big. Most can get almost as tall as thirty feet. Some can get nearly twice as tall. However, they can take more than a century or several centuries to do so. Old specimens around Europe are significantly older than two thousand years. Slow growth is an advantage for formal hedges that get shorn only annually. English yew prefers regular watering. Partial shade is not a problem.

Irish yew is actually a cultivar of English yew with densely upright growth. The various golden yews have yellowish foliage. Otherwise, most English yews have finely textured dark green foliage on angular stems that resemble those of redwood. Individual leaves are very narrow, and only about half and inch to an inch long. The peeling dark brown bark resembles that of large junipers, but not quite as shaggy. English yew is toxic.